"Boneless" means that no one has a backbone. This is from the mouth of Yu Xun, a famous politician and strategist at the end of the Eastern Han Dynasty in the Three Kingdoms period. Seeing that Cao Cao was ambitious and could achieve great things, he wholeheartedly assisted him, hoping that he could revive the Han Dynasty. However, when Cao Cao became more and more powerful, all his ministers hoped that Cao Cao would abolish the emperor and become king, but Yu Xun opposed it. However, none of the ministers loyal to the Han dynasty dared to speak out against it, saying that "there are no bones left", which means that these people have no backbone, they are all trying to preserve their sanity and are afraid of Cao Cao's power, and they have all been killed.